Confusion about TON and Etherium

Hi,

I am having confusion about TON and Etherium in general. A while back I decided to buy TON. Except, Coinbase did not support it. I was told to use Coinbase Wallet. So, I converted into USDC and send it to my wallet. After a lot of trial and error I figured that: – you need to buy Etherium – you need to have it on Etherium network – and only then you can buy TON coin on Etherium network

I find it very confusing why Wallet was telling me that I can only swap TON coin on Etherium and I needed to use Etherium to pay for gas. Doesn't TON coin have its own TON network? Why wass Coinbase required me to transfer Etherium into a wallet and then only allowed to swap on Etherium network?